An image forming device includes a toner saving mode that converts embedded pixels to a lighter density based on an embedded pixel template and an embedded pixel image data value. An embedded pixel is a pixel surrounded by a number of neighboring pixels that have the same image data value as the surrounded pixel. The embedded image data value can be predetermined or selectable. The image data value preferably corresponds to a black pixel. The image data value of the identified embedded pixels is altered to an output image data value corresponding to a lower density. The altered image data value preferably corresponds to a white pixel. The template used to identify the embedded pixel preferably includes a center pixel of interest and the four edge-adjacent neighboring pixels. The image forming device, when in the toner save mode, thus prints embedded pixel areas originally having a density at least equal to the embedded image data value at the lower density output image data value. Thus, less toner is used in the toner save mode.
Legal claims defining the scope of protection, as filed with the USPTO.
1. A method for converting data values of embedded pixels of an image, the embedded pixels having data values at least equal to a first data value, the method comprising: inputting a pixel of interest and a number of pixels neighboring the pixel of interest; comparing data values of the pixel of interest and the neighboring pixel to at least one embedded pixel template; determining, based on the comparison, if the pixel of interest is an embedded pixel having a data value at least equal to the first data value; converting, when the pixel of interest is an embedded pixel having a data value at least equal to the first data value, the data value of the pixel of interest to a second data value representative of a lower density image pixel; and repeating the inputting, comparing, determining and converting steps for at least one other pixel of the image.
2. The method of claim 1, further comprising inputting or selecting first data representing the first data value.
3. The method of claim 2, wherein inputting or selecting the first data comprises inputting the first data from a user.
4. The method of claim 2, wherein inputting or selecting the first data comprises selecting the first data through a display screen or graphical user interface screen.
5. The method of claim 1, further comprising inputting or selecting second data representing the second data value.
6. The method of claim 5, wherein inputting or selecting the second data comprises inputting the second data from a user.
7. The method of claim 6, wherein inputting or selecting the second data comprises selecting the second data through a display screen or graphical user interface screen.
8. The method of claim 1, wherein the first data value is predetermined.
9. The method of claim 1, wherein the second data value is predetermined.
10. The method of claim 1, wherein determining if the pixel of interest is an embedded pixel comprises determining if the data value of the pixel of interest and the neighboring pixels are all equal to the first data value.
11. The method of claim 1, wherein determining if the pixel of interest is an embedded pixel comprises: determining if the data values of the neighboring pixels are all equal to the data value of the pixel of interest; and determining if the data value of the pixel of interest is at least equal to the first data value.
12. The method of claim 11, wherein determining if the data value of the pixel of interest is at least equal to the first data value includes determining, when the data value of the pixel of interest is not equal to the first data value, if the data value of the pixel of interest is between the first data value and the data value of a black pixel.
13. The method of claim 11, wherein determining if the data value of the pixel of interest is at least equal to the first data value includes determining, when the data value of the pixel of interest is not equal to the first data value, if the data value of the pixel of interest is less than the first data value.
14. The method of claim 11, wherein determining if the data value of the pixel of interest is at least equal to the first data value includes determining, when the data value of the pixel of interest is not equal to the first data value, if the data value of the pixel of interest is greater than the first data value.
15. The method of claim 1, wherein the first data value represents a black image pixel.
16. The method of claim 1, wherein the second data value represents a white image pixel.
17. An apparatus that converts data values of embedded pixels of an input image to data values representing a lower density comprising: an image data storing device; a template-matching circuit including at least one embedded pixel template, the template-matching circuit inputting image data representing a pixel of interest and a number of neighboring pixels and outputting a first signal having an image, wherein a value of the first signal indicates whether the pixel of interest is an embedded pixel based on a comparison between the at least one embedded pixel template and the pixel of interest and neighboring pixels; and a look-up-table circuit that inputs the first signal and an image value of the pixel of interest, and outputs a second signal having an image value, wherein the image value of the second signal is representative of a lower density image pixel when the pixel of interest is an embedded pixel.
18. The embedded pixel converting apparatus of claim 17, further comprising a pulse-width, position-modulation circuit that inputs the second signal and outputs a pulse width and position modulated signal.
19. The embedded pixel converting apparatus of claim 18, further comprising an image forming engine that inputs the pulse width and position modulated signal and outputs an image having embedded pixels printed at a lower density than the data values for the embedded pixels in the output image.
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May 12, 1998
July 24, 2001
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